<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }
    
    .box1 {
        float: left;
        width: 75%;
        height: 100px;
        border: 1px solid red;
        
        
    }
    .box2 {
        float: left;
        width: 50%;
        height: 200px;
        border: 1px solid red;
        
       

        
    }
    .box3 {
        float: left;
        width: 25%;
        height: 400px;
        border: 1px solid red;
        
        
    }
    .box4 {
        float: left;
        width: 25%;
        height: 100px;
        border: 1px solid red;
     
    }



    .box5 {
        width: 100px;
        height: 100px;
        background-color: pink;

        border-top: 100px solid yellow;
        border-right: 100px solid green;
     
        border-left: 100px solid red;
    }
    
</style>
<body>
    <div class="box1"></div>
    <div class="box2"></div>
    <div class="box3"></div>
    <div class="box4"></div>

    <div class="box5"></div>
</body>
</html>